Roadway conditioning apparatus

ABSTRACT

A surface conditioning attachment for a motor grader or the like for use in maintenance operations on gravel roadways comprises a gang of harrow disks carried on a support shaft, there being a support structure for deploying said disks laterally outwardly of the grader at an angle to the direction of travel and with the concave sides of the disks facing forwardly. In use the gang of disks engages the surface of the road shoulder and cuts up and moves gravel and vegetation thereon laterally towards the roadway.

This application is a .Iadd.reissue of application Ser. No. 07/872,145,now U.S. Pat. No. 5,197,820, which was a .Iaddend.continuation, ofapplication Ser. No. 07/639,350, filed Jan. 10, 1991, now U.S. Pat. No.5,108,221.

BACKGROUND OF THE INVENTION

a. Field of the Invention

This invention relates to a new or improved surface conditioningattachment for use with roadway maintenance equipment, in particular inmaintenance operations on gravel .Iadd.or nonpaved .Iaddend.roadways.

b. Description of the Prior Art

A major problem in maintaining a gravel road is that of trying toprevent the gravel from being lost into the ditches bordering the roador from accumulating on the road shoulder in the form of a ridge orberm. It is also important to control the spreading of vegetation suchas grass and weeds on the road shoulders so that it does not creep ontothe road surface.

With constant maintenance by means of a motor grader or the like, aridge or berm of displaced gravel and like material is produced on theedge of the road. This berm prevents water from running freely off theside of the road, and as a result cuts are formed by escaping water, andgravel is lost in these cuts.

The present methods used to control these problems involve the use ofherbicides for controlling growth of vegetation on road surfaces.However this entails a problem since the herbicides cannot be containedbecause of the leeching which occurs, and as a result too muchvegetation is killed which causes spreading of the roadway.Additionally, herbicides cannot be used near water ways.

Vegetation growth on gravel road shoulders can also be controlled byvarious types of mulchers. However mulching requires specializedequipment, and although mulching will cut up the vegetation and mix itwith the gravel, this is only a temporary solution, and is a costly oneto repeat.

Accordingly, the most common approach applied is to periodicaly attemptto retrive the road gravel from the shoulders using a motor grader, butthis solution also causes grass and sod to be moved onto the roadway bythe grader. Such material will not spread and therefore lumps are leftat the side of the road. The presence of lumps of sod, grass and loosegravel on the side of the road in turn causes vehicle operators to steerwell clear of the road shoulders, and this in turn raises the risk ofcollisions between vehicles travelling in opposite directions.

SUMMARY OF THE INVENTION

The present invention provides a surface conditioning attachment for usein surface maintenance operations on a gravel roadway, said attachmentcomprising a gang of dished harrow disks rotatably supported at uniformspacing on a support shaft, and a support structure carrying saidsupport shaft, means for mounting said support structure on .[.theright-hand side of.]. a carrying .Iadd.or pulling .Iaddend.vehicle todeploy the shaft generally parallel to the surface to be conditioned andoblique to the direction of travel of the vehicle, the concave sides ofthe disks .[.preferably.]. being oriented towards the front and theshaft diverging from the vehicle in the rearwards direction, such thatin use the apparatus will engage and condition a swath of roadway .[.tothe right outboard side of the vehicle.]. surface material from saidswath being conditioned and displaced in the direction of the middle ofthe roadway.

The attachment can be mounted on a motor grader or other roadconditioning vehicle, and .[.since it mounts on the right side of thevehicle,.]. the vehicle can progress in normal fashion along theright-hand side of the road, and therefore does not present a hazard tooncoming traffic.

The support .[.shaft.]. .Iadd.structure .Iaddend.carrying the disks isattached at its forward end to the vehicle, its oblique arrangementbeing maintained by a brace member extending from the rear of the.[.vehicle.]. .Iadd.support structure .Iaddend.to the rear mounting ofthe shaft, this brace member preferably being adjustable in length sothat the angle between the shaft and the fore-and-aft direction of thevehicle can readily be adjusted in the range between about 15 and 35degrees. A preferred angle is about 25 degrees. Preferably means areprovided for raising the attachment from the ground level and pivotingit inwardly toards the vehicle to a retracted position for transport.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will further be described, by way of example only, withreference to the accompanying drawings wherein:

FIG. 1 is a plan view of the attachment;

FIG. 2 is a side perspective view thereof;

FIG. 3 is an enlarged fragmentary side view of the rear portion of theattachment;

FIG. 4 is a side perspective view of the attachment mounted on a motorgrader; and

FIG. 5 is a schematic plan view illustrating the attachment in use.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1 to 3, the attachment generally indicated at 10comprises a gang of uniform, parallel, concavely dished harrow disks 11rotatably mounted on a shaft 12, the individual disks being uniformlyspaced by means of annular spacers 13 arranged between them. The shaft12 extends parallel to and spaced below a frame formed by a steel I-beam14. The forward end of the shaft is rotatably received in a bearing (notshown) in a bracket 15 which depends from the front end of the I-beam14, and the rearward end of the shaft is supported in a thrust bearing17 in a bracket 18 depending from the rearward end of the beam 14. Thebracket 18 also supports two laterally spaced mounting lugs 19.

The forward bracket 15 also supports a downwardly angulated arm 21 thelower end of which supports a ground wheel 22 rotatable on a horizontalaxis.

An attaching arm 23 extends angularly from the front bracket 15, andcarries at its free end a suitable means for attachment to a motorgrader or like vehicle, the attachment means here being show as a swivelball attachment 24. An angulated strut 25 is attached at its ends insuitable manner, as by welding, to both the arm 23 and the beam 14 tomaintain these elements in the predetermined angular relationship shownin FIG. 1. In use, the attachment is mounted on a suitable vehicle suchas a motor grader 26 (as shown in FIG. 4). The attachment is mounted onthe right-hand outboard side of the motor grader to the rear of the moldboard blade 27. Specifically, the swivel ball connector is attached tothe lower end of the snow plough mast 28 that extends vertically at theside of the motor grader, so that the attachment end can be raised orlowered on this mast to position it at the desired height. The rear endof the attachment 10 is supported by a brace 29 one end of which ispivoted to a mounting 30 on the grader, and the other end of which ispivoted to one of the lugs 19 on the bracket 16. By virtue of thismounting, the attachment can be swung from the horizontal operatingposition, wherein the gang of disks 11 lie generally horizontally incontact with the ground, and the retracted position as shown in FIG. 4wherein the attachment is swung upwardly and inwardly towards the sideof the grader for transportation. A powered cable means (not shown) isprovided on the mast 28 or on any other suitable part of the grader toeffect raising of the attachment when desired.

In use, the grader hydraulic controls are manipulated to lower themounting point at the swivel ball 24 downwardly until the ground wheel22 of the attachment rests upon the ground. Thereafter the beam 14 isallowed to swing downwardly and outwardly until the disks 11 rest uponthe ground surface to be treated. In this configuration the attachmentof the will be deployed substantially as illustrated in FIG. 5 extendingobliquely to the fore-and-aft direction by a selected angle (asillustrated, about 25 degrees), being supported in this position by thebrace 29. The angular orientation of the attachment can be varied byconnecting the brace to one or other of the mounting lugs 19.Alternatively the brace may be designed to be of adjustable length toprovide a continuous range of angular adjustment from about 15° to 35°.

As will be seen, the leading of the disk gang 11 is spaced laterallyfrom the side of the motor grader by the attaching arm 23, so that thefirst of the disks 11 registers with the right edge of the mold boardblade 27, it being noted that the disks are oriented with their concavesides facing frontwards. The angle between the orientation of the diskgang 11 and the fore-and-aft direction can be varied from the example of25 degrees that is shown, this variation being made in accordance withthe desired amount of cut that each disk is to make, and also of theswath that is conditioned by the attachment as the motor graderadvances.

The attachment is used in combination with the normal grading operationof the road which is carried out using the mold board blade 27. As themotor grader advances the disks 11 are engaged by the surface of theshoulder, cutting a swath of approximately 32 inches, and moving thegravel and newly mulched material inwards, i.e. towards the center ofthe road. The amount by which the cut material is moved laterallyinwardly will vary according to the orientation of the disk gang 11 tothe fore-and-aft direction, and also according to the speed of advancein the forward direction. The faster the speed the further the cutmaterial will be displaced laterally. Preferably these conditions areset so that the newly mulched material is moved laterally by from 12 to16 inches. During this operation, the disks are of course turned byinteraction with this material, the disks turning in the clockwise senseas viewed from the rear end of the shaft 12. The material cut by thedisk gang is turned and mulched, and left to dry so that on a subsequentpass of the grader over the same path, the previously cut and now driedmaterial is displaced inwardly by a further 12 to 16 inches so that theoutermost 12 to 16 inches of the swath is swept clean. On subsequentpasses the entire 32 inch swath will be swept clean, effectivelyretrieving surface gravel from the shoulder of the road and distributingit back onto the roadway as well as preventing berm buildup on theshoulder and removing vegetation.

The .[.retriever.]. .Iadd.disk .Iaddend.attachment is of sufficient massthat the disks will cut into the surface of the road shoulder ratherthan merely slide over it, and readily accommodates to the inclinationof the road or shoulder surface over which the attachment is drawn, evenif this inclination differs from that of the surface beneath the.[.grader.]. .Iadd.vehicle.Iaddend.. This is because of the pivotalmounting of the attachment on the .[.grader.]. .Iadd.vehicle..Iaddend.

Regular use of the .[.retriever.]. .Iadd.disk .Iaddend.attachmenteliminates the buildup of sod and loose gravel on the shoulder of theroadway and spreads reusable material such as gravel back onto theroadway.

The attachment can of course be used independently of its use on a motorgrader as described above, and is readily adaptable for mounting onother road vehicles such as trucks, snow ploughs and the like.

The mount of the wheel 22 can be designed to provide for verticaladjustment of the wheel relative to the shaft 12, although since thelower side of the wheel should preferably be at the same level as thelower sides of the disks, generally adjustment will only be necessary tocompensate for wear of the disks.

I claim:
 1. A surface conditioning attachment for use in surfacemaintenance operations on a gravel roadway, said attachment comprising:agang of dished, harrow disks rotatably supported at uniform spacing on asupport shaft; a support structure carrying said support shaft; meansfor mounting said support structure generally at the side of anassociated carrying vehicle to deploy the shaft generally parallel tothe surface to be conditioned, and oblique to the direction of travel ofthe vehicle so that said shaft diverges from the vehicle in a rearwarddirection .Iadd.at an angle between said shaft and the fore-and -aftdirection of the vehicle in the range of 15 to 35 degrees; .Iaddend.brace means extending between the associated vehicle and a portion ofsaid support structure spaced from said vehicle, for thereby maintainingsuch shaft in said .[.generally.]. oblique orientation relative to thedirection of travel of the vehicle; said concave sides of said disksoriented toward the direction of travel of said associated vehicle andsaid attachment, such that in use the apparatus will engage andcondition a swath of roadway to the outboard side of the associatedvehicle, with surface material from said swath being conditioned anddisplaced in the direction of the middle of the roadway.
 2. The surfaceconditioning apparatus in accordance with claim 1, whereinsaid bracemeans is of an adjustable length to permit the orientation of saidsupport structure, relative to said vehicle, to be selective varied. 3.The surface conditioning attachment in accordance with claim 1,includingground engaging means carried on the attachment in the regionof the forwardly positioned end of said shaft, said ground engagingmeans being positioned to support said shaft so that said disks cut intothe ground that is to be broken up and moved inward.
 4. A surfaceconditioning attachment for use in surface maintenance operations on agravel roadway, said attachment comprising:a gang of dished, harrowdisks rotatably supported at uniform spacing on a support shaft; asupport structure carrying said support shaft; and means for attachingsaid support structure on an associated carrying vehicle to deploy theshaft generally parallel to the surface to be conditioned, and formaintaining said support structure oblique to the direction of travel ofthe vehicle so that said shaft diverges from the vehicle in a rearwarddirection .Iadd.at an angle between said shaft and the fore-and-aftdirection of the vehicle in the range of 15 to 35 degrees .Iaddend.;said attaching means including mounting means for pivotally mountingsaid support structure so that said support structure can be raised andlowered relative to said associated carrying vehicle; said concave sidesof said disks oriented toward the direction of travel of said associatedvehicle and said attachment, such that in use, the apparatus will engageand condition a swath of roadway, with surface material from said swathbeing conditioned and displaced in the direction of the middle of theroadway.
 5. The surface conditioning apparatus of claim 4, whereinsaidattaching means further includes brace means extending between theassociated vehicle and a portion of said support structure spaced fromsaid vehicle, for thereby maintaining said shaft in said generallyoblique orientation relative to the direction of travel of the vehicle.6. The surface conditioning attachment of claim 4, including:groundengaging means carried on the attachment in the region of the forwardlypositioned end of said shaft, said ground engaging means beingpositioned to support said shaft so that the disks cut into the groundthat is to be broken up and moved inward.
 7. The surface conditioningattachment of claim 5, including:ground engaging means carried on theattachment in the region of the forwardly positioned end of said shaft,said ground engaging means being positioned to support said shaft sothat the disks cut into the ground that is to be broken up and movedinward. .Iadd.8. A surface conditioning attachment for use inassociation with a carrying vehicle in surface maintenance operations ona nonpaved road surface, said attachment comprising: a gang of dishedharrow disks rotatably supported on and uniformly spaced along a supportshaft, said support shaft having a forward end and a rear end and saidharrow disks being oriented with the concave sides thereof facing saidforward end; a support structure carrying said support shaft; and meansfor mounting said support structure to said associated carrying vehicleto deploy the shaft generally parallel to the surface to be conditionedand oblique to the direction of travel of the vehicle with the shaftdiverging rewardly at an angle of between 15 and 35 degrees to saiddirection of travel. .Iaddend. .Iadd.9. The surface conditioningapparatus of claim 8, wherein the support structure is deployed to theoutboard side of the associated carrying vehicle. .Iaddend. .Iadd.10.The surface conditioning apparatus of claim 9 wherein the supportstructure is deployed to deploy the shaft at angle of about 25 degreesto said direction of travel. .Iaddend. .Iadd.11. The surfaceconditioning apparatus of claim 10, wherein said means for mounting saidsupport structure to said associated carrying vehicle further includesbrace means extending between the associated vehicle and a portion ofsaid support structure spaced from said vehicle for thereby maintainingsaid shaft in said generally oblique orientation relative to thedirection of travel of the vehicle. .Iaddend. .Iadd.12. The surfaceconditioning apparatus of claim 11, wherein said brace means isadjustable in length to thereby adjust the angle of said shaft withrespect to the direction of travel or the vehicle. .Iaddend.